In the 19th century, New Brunswick became the new home of several thousand immigrants, most of whom were emigrating from Scotland and Ireland. As a result, the population of New Brunswick rose from 25,000 in 1805 to 193,000 in 1851. One of the original provinces when the Dominion of Canada was declared in 1867, New Brunswick was also home to a large Roman Catholic population. One of the oldest buildings in New Brunswick, the Christ Church Cathedral in Fredericton has a storied history. The building is an example of the Gothic Revival architectural style in Canada. Like so many others constructed at the time, the Christ Church Cathedral was an attempt to revive Medieval church designs. The project began in 1845, but the building was not completed and consecrated until 1853. The church was affected by several natural disasters, including a lightning strike in 1911 which caused significant damage. It took over a year to complete the repairs. In 2006, a fire in the bell tower caused damage to the choir and resulted in the church closing for repairs. Located in the heart of Fredericton, the Christ Church Cathedral was declared a National Historic Site in 1983 by the Historic Sites and Monuments Board of Canada.

New Brunswick’s extensive coastal region makes the fishing industry an important part of the province's economy. As one of the largest industries in New Brunswick, fisheries have always been a key part of the province’s long history. Around the turn of the century, cod and lobster rushes resulted in a sharp decline in those resources. Concerns about scarcity provoked worry and controversy around regulations regarding fishing and the use of coastal waterways. As fishing became a more significant industry, these issues grew. New rules put in place affected Indigenous peoples on the East Coast more than anyone, adding to the long-standing tensions between Euro-Canadian settlers and local Indigenous groups. Following Confederation in 1867, Indigenous peoples were systematically excluded from the Atlantic salmon harvest for the remainder of the 19th century. Many Indigenous fishing methods were banned to prevent them from "destroying the salmon fishery." As expected, the regulations that stripped Indigenous fishing rights caused controversy in Eastern Canada for several years. Despite powerful forces discouraging them, Indigenous peoples continued to engage in the fishing and hunting industries using their traditional (but now illegal) methods.

The lumber industry is another important sector of New Brunswick's economy. The province is primarily covered in balsam fir, red and black spruce, pine, and hemlock. With abundant access to trees, the lumber industry has played an important economic and cultural role within New Brunswick. Access to wood and wood processing methods were important in the early-19th century when shipbuilding was an important and profitable industry. Shipbuilders took advantage of the province's extensive forests in order to construct and sell the massive ships used for transporting goods and people around the globe. Interestingly, some of the vessels used to transport New Brunswick’s various domestic products were made entirely from the province’s lumber.